In Firefox 3, JavaScript execution is already 20% faster than in Firefox 2. That's great, but it's minimal compared to the speedups coming in future Firefox versions, thanks to a new JavaScript rendering engine called TraceMonkey now in development at Mozilla (Firefox 3's JavaScript rendering engine is known as SpiderMonkey).

Techspot.com reports that the new TraceMonkey JavaScript execution engine coming in future versions of Firefox will provide at least a 2x performance increase over SpiderMonkey, based on information posted by Mozilla's Mike Shaver (its VP of Engineering). However, that might be a conservative estimate. Shaver reports that TraceMonkey runs core JavaScript primitives such as function call, global loop, and empty loop at at speeds over 20 times faster than in Firefox 3. Benchmark performance (see figure accompanying this article) is just as impressive. According to Shaver:

The goal of the TraceMonkey project — which is still in its early stages — is to take JavaScript performance to another level, where instead of competing against other interpreters, we start to compete against native code.

So, how long before TraceMonkey elbows SpiderMonkey out of the way as "top monkey" in the Firefox JavaScript execution game? A stripped-down version of TraceMonkey is now being incorporated into Firefox 3.1 (it's turned off by default in current builds), but the full version of TraceMonkey won't see the light of day until version 4.0, according to Techspot.com.

Faster JavaScript execution could mean a much smarter (as well as faster) web browser. What would you like to see the code jockeys at Mozilla and elsewhere do with all that extra speed? Hit the comments button and let us know.

Comment

...is for Mozilla to implement an easy to access UserChrome and UserContent editor with syntax highlights and drop-down code suggestions. I'm tired of having to switch between 3 windows to edit them. Also, if code executes much faster, UserContent could be edited heavily without a performance hit.